An electrical substation is a subsidiary station of electricity generation, transmission and distribution where voltage is transformed from high to low or vice-versa using transformers. Electrical substations are usually provided with a control module which monitors and controls the different elements of the substation, such as disconnect switches. Because a malfunction of a disconnect switch may damage the electrical substation, the position of the arm of the disconnect switch is usually monitored by a sensor positioned adjacent to the disconnect switch. However, in some instances, the position of the arm is not sufficient for determining that the disconnect switch does not operate adequately.
Therefore, there is a need for an improved method and apparatus for detecting an abnormality of a high voltage switch.